The invention relates to a rotary slide valve for servo-assisted steering systems of motor vehicles.
In known rotary slide valves of the type mentioned in the introduction (DE 198 08 796 A1), the input element of the valve is connected to the steering column and the output element, which adjoins the steering mechanism, is connected to the input element in a manner which can be twisted as a function of the torque, the input and output elements being coupled via a torsional spring and in a manner with a limited rotational angle. Furthermore, the input element is coaxially and fixedly to a rotary slide so as to rotate with it, the latter for its part forming the guide for a control sleeve which is fixedly connected to the output element so as to rotate with it, so that rotary movements between the input element and output element influence the degree of congruence of crossflow openings which are provided in the rotary slide and control sleeve.
A radial coupling pin serves to fixedly connect the control sleeve to the output element so as to rotate with it, said radial coupling pin being fixed in the output element in the axial region of congruence of the control sleeve and output element and being inserted into a receptacle of the control sleeve during assembly in such a way that there is a connection which is fixed in terms of rotation and as free of play as possible. The coupling pin is configured as a clamping pin and therefore requires a tight tolerance with respect to the receptacle, in order to achieve the aimed at freedom from play with regard to the torques to be transmitted, which makes assembly by radial insertion of the coupling pin into the receptacle with eccentric positioning of the output element with respect to the control sleeve more difficult and necessitates appropriate radial free spaces.
In JP-A-11208491, the receptacle for the coupling pin in the control sleeve tapers axially, starting from an entry cross section of excess dimensions compared with the coupling pin, to a cross section which is smaller than the cross section of the coupling pin and the coupling pin is clamped in a play-free position in the tapered cross-sectional area.